Answer:
The opposite of the word lack is sufficient.
Lack is the state where resources are inadequate and fail to meet one's expectations or fail to meet the need or conditions.
Example:
Lack of interest to listen to students
Example:
tank contains enough water.
There is enough space to sit in the vehicle.
enough food is made for guests at home tonight.
There is enough airflow inside the house.
is synonymous with sufficient: